similar to: [PATCH] vhost: copy_from_user -> __copy_from_user

From: Michal Hocko <mhocko at suse.com> vhost driver relies on copy_from_user/get_user from a kernel thread. This makes it impossible to reap the memory of an oom victim which shares mm with the vhost kernel thread because it could see a zero page unexpectedly and theoretically make an incorrect decision visible outside of the killed task context. Make sure that each place which can read

From: Michal Hocko <mhocko at suse.com> vhost driver relies on copy_from_user/get_user from a kernel thread. This makes it impossible to reap the memory of an oom victim which shares mm with the vhost kernel thread because it could see a zero page unexpectedly and theoretically make an incorrect decision visible outside of the killed task context. Make sure that each place which can read

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace(qemu) implementation of DMA remapping. The idea is simple. When vhost meets an IOTLB miss, it will request the assistance of userspace to do the translation, this is done through: - Fill the translation request in a preset userspace address (This address is set through ioctl

This patch tries to implement an device IOTLB for vhost. This could be used with for co-operation with userspace(qemu) implementation of DMA remapping. The idea is simple, cache the translation in a software device IOTLB (which was implemented as interval tree) in vhost and use vhost_net file descriptor for reporting IOTLB miss and IOTLB update/invalidation. When vhost meets an IOTLB miss, the

Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/net.c | 3 +- drivers/vhost/vhost.c | 539 ++++++++++++++++++++++++++++++++++++++++++++++---- drivers/vhost/vhost.h | 8 +- 3 files changed, 513 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 30273ad..f55c82f8 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@

On Fri, Jun 17, 2016 at 11:00:17AM +0200, Michal Hocko wrote: > From: Michal Hocko <mhocko at suse.com> > > vhost driver relies on copy_from_user/get_user from a kernel thread. > This makes it impossible to reap the memory of an oom victim which > shares mm with the vhost kernel thread because it could see a zero > page unexpectedly and theoretically make an incorrect

If m.num is too large then the "m.num * sizeof(*m.arr)" multiplication could overflow and the access_ok() check wouldn't test the right size. Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com> --- Only needed in linux-next. diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 215a3c0..fdff8f9 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c

If m.num is too large then the "m.num * sizeof(*m.arr)" multiplication could overflow and the access_ok() check wouldn't test the right size. Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com> --- Only needed in linux-next. diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 215a3c0..fdff8f9 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c

When ring parsing fails, we currently handle this as ring empty condition. This means that we enable kicks and recheck ring empty: if this not empty, we re-start polling which of course will fail again. Instead, let's return a negative error code and stop polling. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Dave, I'm sending this out so it can get reviewed. I'll

When ring parsing fails, we currently handle this as ring empty condition. This means that we enable kicks and recheck ring empty: if this not empty, we re-start polling which of course will fail again. Instead, let's return a negative error code and stop polling. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Dave, I'm sending this out so it can get reviewed. I'll

This patch introduces basic support for packed ring. The idea behinds packed ring is to use a single descriptor ring instead of three different rings (avail, used and descriptor). This could help to reduce the cache contention and PCI transactions. So it was designed to help for the performance for both software implementation and hardware implementation. The implementation was straightforward,

On Fri, Mar 25, 2016 at 10:34:34AM +0800, Jason Wang wrote: > This patch tries to implement an device IOTLB for vhost. This could be > used with for co-operation with userspace(qemu) implementation of DMA > remapping. > > The idea is simple. When vhost meets an IOTLB miss, it will request > the assistance of userspace to do the translation, this is done > through: > >

On Fri, Mar 25, 2016 at 10:34:34AM +0800, Jason Wang wrote: > This patch tries to implement an device IOTLB for vhost. This could be > used with for co-operation with userspace(qemu) implementation of DMA > remapping. > > The idea is simple. When vhost meets an IOTLB miss, it will request > the assistance of userspace to do the translation, this is done > through: > >

Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f437..4d379ed 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -33,8 +33,8 @@ enum { VHOST_MEMORY_F_LOG = 0x1, };

Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f437..4d379ed 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -33,8 +33,8 @@ enum { VHOST_MEMORY_F_LOG = 0x1, };

What it is: vhost net is a character device that can be used to reduce the number of system calls involved in virtio networking. Existing virtio net code is used in the guest without modification. There's similarity with vringfd, with some differences and reduced scope - uses eventfd for signalling - structures can be moved around in memory at any time (good for migration) - support memory

What it is: vhost net is a character device that can be used to reduce the number of system calls involved in virtio networking. Existing virtio net code is used in the guest without modification. There's similarity with vringfd, with some differences and reduced scope - uses eventfd for signalling - structures can be moved around in memory at any time (good for migration) - support memory

From: Al Viro <viro at zeniv.linux.org.uk> it has just verified that it asks no more than the length of the first segment of iovec. And with that the last user of stuff in lib/iovec.c is gone. RIP. Cc: Michael S. Tsirkin <mst at redhat.com> Cc: Nicholas A. Bellinger <nab at linux-iscsi.org> Cc: kvm at vger.kernel.org Cc: virtualization at lists.linux-foundation.org

From: Al Viro <viro at zeniv.linux.org.uk> it has just verified that it asks no more than the length of the first segment of iovec. And with that the last user of stuff in lib/iovec.c is gone. RIP. Cc: Michael S. Tsirkin <mst at redhat.com> Cc: Nicholas A. Bellinger <nab at linux-iscsi.org> Cc: kvm at vger.kernel.org Cc: virtualization at lists.linux-foundation.org

What it is: vhost net is a character device that can be used to reduce the number of system calls involved in virtio networking. Existing virtio net code is used in the guest without modification. There's similarity with vringfd, with some differences and reduced scope - uses eventfd for signalling - structures can be moved around in memory at any time (good for migration, bug work-arounds